Cationic Grafting of Oxazolyl Copolymers with 2‐Methyl and 2‐Phenyl Oxazoline

Summary: Commercial poly(styrene‐ co ‐acrylonitrile) (SAN) and poly(butadiene‐ co ‐acrylonitrile) (NBR) were functionalized with oxazoline groups through a reaction with 1,3‐aminoethylpropanediol (AEPD). Each of the two products, along with a third commercial poly(styrene‐ co ‐vinyl oxazoline) copolymer, went through a reaction with methyl triflate producing stable oxazolinium salts. The products were subsequently used as macroinitiators for the ring‐opening cationic grafting of 2‐methyl and 2‐phenyl oxazoline to produce poly( N ‐acylethylenimine) grafts. The products were characterized by FT‐IR, 1 H NMR and elemental analysis. The grafted fraction varied from 10 to 55 wt.‐%. The monomer units grafted onto each oxazolinium pendant group varied from 3 to 23 depending on the oxazoline substitution and concentration. The results show, firstly, that controlled and reproducible levels of poly( N ‐acylethylenimine) grafts can be incorporated and, secondly, that since these results are general, they are thus applicable to a wide variety of nitrile‐containing polymers.Reaction of a nitrile group to form an oxazoline functionality.